I used a different method to mount my gas tank. I took the time when putting my bike together to get this taken care of from the get go. OK first I got four one inch wide flat fender washers. they fit the tank studs perfectly in the center and have an over hang to allow for a good area to grab ahold of or loop around. Next Second I grinded the edges of all four washers to have a flat straight edge so the flat edge can go arround/grab the lower portion of the bikes tubing.
THIRD put the washers on the studs and use a dab of lock tite and set the nuts to the studs just started on the end of the studs the washers now dangle around freely.
FOURTH go to autozone and get a package of springs the HELP brand. The ones I'm talking about are an assortment of auto type clutch pedal release/return springs and they have a long straight unwinded portion of the spring thats what I used to make a looped end. Set these up with medium tension and in a criss/cross pattern.
FIFTH Now I used a piece of Industrial covering but get yourself a piece of foam or rubber to make a good vibration resistant means of protecting your tank from your frame.
Now I just have to get the bike running.
TNX